3.5 MB 37 page PDF file:
http://www.cherod.com/mustang/HowTo/...tang_specs.pdf
Looking at the Steering Specifications in this document (PDF-page 16, doc-page 14) I see the GT is 2.83 turns lock-to-lock, while the V6 is 3.13. Doesn't seem like much of a difference (just under ten percent), but you got to figure if Mr Ford thought it was important enough to make two versions, there's some kind of value in it.
More of the "V6 purchasers are likely to be less sophisticated and demanding, and less likely to benefit from faster steering"? Or is it "V6 has a greater proportion of its weight on the front wheels so needs more mechanical advantage"? Or something completely different?
What are the physical changes necessary to get that 10% faster steering response? Jack up the grill pony and slide a GT under it? Something less complicated and less costly?
Enquiring mind wants to know.